﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using Microsoft.Win32;

namespace MSWebBroswerEx
{
    internal struct Struct_INTERNET_PROXY_INFO
    {
        public int dwAccessType;
        public IntPtr proxy;
        public IntPtr proxyBypass;
    }
    internal class ProxyHelper
    {
        [DllImport("wininet.dll", SetLastError = true)]
        private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);

        public void RefreshIESettings(string strProxy) 
        { 
            const int INTERNET_OPTION_PROXY = 38; 
            const int INTERNET_OPEN_TYPE_PROXY = 3; 

             Struct_INTERNET_PROXY_INFO struct_IPI; 

            // Filling in structure 
            struct_IPI.dwAccessType = INTERNET_OPEN_TYPE_PROXY; 
             struct_IPI.proxy = Marshal.StringToHGlobalAnsi(strProxy); 
             struct_IPI.proxyBypass = Marshal.StringToHGlobalAnsi("local"); 

            // Allocating memory 
            IntPtr intptrStruct = Marshal.AllocCoTaskMem(Marshal.SizeOf(struct_IPI)); 

            // Converting structure to IntPtr 
            Marshal.StructureToPtr(struct_IPI, intptrStruct, true); 

            bool iReturn = InternetSetOption(IntPtr.Zero, INTERNET_OPTION_PROXY, intptrStruct, Marshal.SizeOf(struct_IPI)); 
         }
        public string GetProxyString()
        {
            RegistryKey key = Registry.CurrentUser;
            RegistryKey ieSetting = key.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings", true);
            object isEnabledProxy = ieSetting.GetValue("ProxyEnable", 0);
            if (isEnabledProxy != null && isEnabledProxy.ToString().Equals("1"))
            { 
                //get proxy string
                object str = ieSetting.GetValue("ProxyServer", "");
                if (str != null && !string.IsNullOrWhiteSpace(str.ToString()))
                {
                    return str.ToString();
                }
            }
            return string.Empty;
        }
    }
}